Optimization of Industrial Robot Trajectory in Composite Production

Currently, traditional materials (e.g. iron, steel, aluminium alloy, wood) are increasingly being replaced by composites in many industrial areas. The main advantages of these new materials are their light weight, high strength and flexibility, corrosion resistance, long lifespan and the reduced price of the produced components. This article discusses the quality of the manufacturing process technology of a shaped composite in 3D space. The technology used is based on a winding of carbon filaments on a polyurethane frame with a circular cross-section (this type of composites is used, for example, in automotive chassis). One important factor in composite frame quality is making the correct winding angles of fibres on the frame and the homogeneity of the individual winding layers. The composite frame is attached to the end-effector of the robot and successively passes through the fibre-processing head during the winding process with three layers. Each layer of fibres is wound at a different angle (usually at π/4, 0 and - π/4). The mathematical model of the winding process and the matrix calculus (especially matrices of rotations, translates and calculations of Euler angles) are used to determine the optimized 3D trajectory of end-effector in this paper. The differential evolution algorithm is applied to finding the optimized 3D trajectory of the end-effector. In this way the winding angles and homogeneity of winding layers are maintained during production of the frame composite. The optimized end-effector trajectory is defined by calculated sequence of tool-centre-point values. The calculation of optimized trajectory is programmed and tested in the Delphi development environment. This approach to determining the optimized trajectory of the robot is substantially more effective than the repeated search of a suitable trajectory using the control panel (teach pendant) of the robot.